1. Field of the Invention
This invention relates generally to optical fibers, and, more particularly, to an optical fiber patch box.
2. Description of the Related Art
With the advent of digital signal communications, optical fiber systems are evolving to meet demand including improved cable designs and reduced operating costs. Thus, more and more, data communication systems traditionally serviced by copper wire connections for digital and analog signaling are being replaced by systems using fiber optic cables. Fiber optic connections are no longer used solely for proprietary telecommunication lines and circuits and are being used in many other industries and applications.
One drawback to all of this growth is that the applications and uses for fiber optic systems have outpaced system designs for all of these new system configurations. One such area is in the use of fiber optic systems in the area of industrial feedback and control systems in which peripheral devices such as, sensors and operative switches and other devices, now communicate with control devices through fiber optic connections. The controllers, having optic, electrical or electro-optic circuitry, are maintained in a housing or cabinet. Presently, the connection of these systems is made through the use of a conventional patch panel developed for the telecommunications industry. While fit for its originally intended purpose in the telecommunications field, the patch panel allows for fibers to be spliced and connected together thereby providing a connection for the digital signals to pass there through. A patch panel connection usually requires a dust free environment and the preparation of fiber optic ends with a sufficiently precise end surface to ensure that TIR (Total Internal Reflection) of the optic signal is maintained when two fibers are connected together. The conventional patch panel has drawbacks in the industrial field where the environment does not necessarily have the same generally clean environment used by the telecommunications industry. Additionally, patch panels are usually intended to be rack mounted while most industrial housings are configured for rail-mounted components. Furthermore, the preparation of the fiber optic cable usually requires a specially trained technician to splice the optical fibers into the patch panel.
When a fiber optic cable breaks during normal use, the technician must be called out to replace the cable in the patch panel. For operations and businesses where such occurrences are rare, the cost of keeping a technician on site is cost prohibitive; however, when a brake occurs there can be a considerable down time associated with the break as a technician must be called in to replace the cable.
One solution to this problem has been the development of a pre-terminated patch panel with a non-removable ribbon cable input lead; however, these pre-terminated patch panel designs have been developed for wide range of applications. While fit for many general applications, such pre-terminated patch panels have limitations in the industrial control systems industry. One issue is the use of non-removable ribbon cable to connect with outside lines. Such non-removable cable, while providing an extension to the patch panel when needed for replacing existing patch panel rack configurations that can use a larger footprint, are not desired in the cramped space of a controller cabinet. The ribbon cable must often be threaded around other cables and components in the cabinet in a manner that maintains the minimum bend radius of the cable. Moving or adding components may result in movement leading to breakage, or actual breakage of, the ribbon cable requiring replacement of the entire pre-terminated patch panel. Furthermore, such devices are not configured for cabinets that use rail mounting of components and require that special mounting brackets be installed in the cabinet, often away from other components. Such configurations result in wasted or lost space within the cabinet.
Thus, the need exists for a way to provide a pre-terminated patch panel that retains all of the design benefits for ease of installation and durability while correcting the problems with installation in cabinets that have been identified above.